<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <button data-a="10" data-b="20" data-c="30">按钮</button>
    <script>
        // data-xxx 自定义数据 h5标准新增的
        var btn = document.querySelector('button');
        console.log(btn.dataset);
    </script>
</body>
</html>